Systems and methods for location of objects

ABSTRACT

Systems and methods that may be employed to visually locate and/or track objects equipped with active RFID tags. The disclosed systems and methods may employ an articulated camera/s, such as closed circuit television (“CCTV”) or other suitable type of articulated camera/s, that is equipped with an antenna array.

This patent application is a continuation of U.S. Ser. No. 10/732,174,entitled “SYSTEMS AND METHODS FOR LOCATION OF OBJECTS”, filed on Dec.10, 2003 now U.S. Pat. No. 7,151,454, which claims priority to copendingU.S. Provisional Patent Application Ser. No. 60/437,713, filed Jan. 2,2003, and entitled “SYSTEMS AND METHODS FOR LOCATION OF OBJECTS” byWashington, the entire disclosure of each of the foregoing beingincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to systems and methods forlocating objects, and in one exemplary application to asset locatingsystems.

Active Radio Frequency Identification (“RFID”) is presently in use todayto locate assets. These assets are typically critical use or expensiveitems that are otherwise difficult or labor intensive to locate.Examples of RFID applications include location of assets in crowdedfactory environments, location of shipping containers and updating thelocation of a shipping container as the container is moved pastdifferent fixed RFID receiver stations, and location of critical medicalequipment.

Existing RFID systems typically include transceivers and a computer orPC based application. The RFID transceivers use signal strength andround trip timing to get a rough triangulation of an article tagged witha RFID tag. Once the overall system (transceivers and PC basedapplication) has been “trained” or calibrated to “know” the relativepositional relationship between transceivers then the general area wherethe article is located can be found in a two dimensional manner, using afloor plan of the area, such as the article is located on the west sideof incoming inspection area, or the article is located at dock #3.However, only limited article location capability is provided byexisting RFID systems, and the information provided by existing RFIDsystems is only useful when the system also has access to a floor planof the area.

SUMMARY OF THE INVENTION

Disclosed herein are visual locating systems and methods that may beemployed to visually track and/or locate objects (e.g., articles,assets, personnel, vehicles, animals, etc.) equipped with active RFIDtags. The disclosed systems and methods may employ an articulatedcamera/s, such as closed circuit television (“CCTV”) or other suitabletype of articulated camera, that is equipped with an antenna array. Invarious embodiments of the disclosed systems and methods disclosedherein, a number of exemplary features may be advantageously implementedfor object location, alone or in combination.

In various embodiments of the disclosed systems and methods disclosedherein, a number of exemplary features may be implemented, alone or incombination to achieve various advantages over existing RFID locatingsystems. Examples of some of the advantages of the disclosedvisual-based systems and methods over existing RFID locating systems andmethods include, but are not limited to the following:

-   -   1) The disclosed visual locating systems may be configured in        one embodiment to be capable of determining three dimensional        locations of objects. In contrast, existing RFID tracking        approaches can only locate the object in two dimensions.    -   2) The disclosed visual locating systems may be employed in one        embodiment to provide visible verification of the state or        condition of a tagged object, such as article, person or animal.        In contrast, existing RFID tracking techniques do not provide        visible verification of the state or condition of the tagged        article.    -   3) The disclosed visual locating systems may be employed in one        embodiment to provide visible verification of the surroundings        of the tagged object, whereas existing RFID techniques do not        provide visible verification of the surroundings of the tagged        article.    -   4) The disclosed visual locating systems may be configured in        one embodiment for instant use or operation for location of        objects without training or calibration, whereas existing RFID        techniques must be “trained” or configured in order to “know”        the spatial relationship between transceivers.    -   5) In one embodiment, implementation of the disclosed visual        locating systems does not require the use of a floor plan. In        contrast, existing techniques require that a floor plan be        entered into the RFID locating system application so that the        triangulated position may be used to determine the general        location of the article in relation to the floor plan.

In one exemplary embodiment, the disclosed visual locating systems maybe implemented to locate a particular active RFID tagged object withinthe field-of-view of one or more articulated cameras, such as closedcircuit TV cameras. In this embodiment, an array of antennas andassociated tracking circuitry may be placed or otherwise installed orcoupled around the line of sight of the articulated camera/s.Advantageously, this configuration may be implemented to allow forlocation, alignment of the camera line of sight (“LOS”), and for visualobservation of a tagged object without the need for resorting totriangulation from multiple RFID transceivers. For example, a visualimage of the tagged object may be provided within the articulated camerafield of view (“FOV”) by using a differential set of antennas thatreceive the emissions from the active RFID tag and by determining therelationship between the camera LOS and the object location via ascanning mechanism that analyzes the emitted signals from the activeRFID tag.

In another exemplary embodiment, two or more antenna-equipped camerasmay be coupled together or coupled to a common node (e.g., via localarea network “LAN” or any other suitable communication network) to forma wide area multi-camera visual locating system. Upon RFID tagactivation, the wide area system may be interrogated to discern which ofthe multiple cameras are receiving the maximum signal strength from theemitting RFID tag. This information may be used to determine whichcamera/s should perform a location sweep pattern or scan. Whilescanning, the system may be configured to maintain a record of multiplepointing solutions (if more than one exists) and may, for example,present a system operator with an image associated with each solutionsuch that the operator may select the preferable view. Placing a systemoperator in the decision loop advantageously provides a very robustsystem in terms of eliminating false positives. Thus, the disclosedsystems and methods may be advantageously implemented to handlemulti-path problems. This is in contrast to existing non-visual twodimensional RFID systems that also may experience such multi-pathproblems when a tagged article is being triangulated by multiple fixedlocation transceivers, but in which no mechanism exists for verifyingthat the article actually occupies the location indicated.

In various embodiments of the disclosed systems and methods disclosedherein, a number of exemplary object location features may beadvantageously implemented, alone or in combination. Following areexamples of several embodiments that employ one or more of thesefeatures to achieve one or more advantages of the disclosed systems andmethods: 1) A pan-tilt-zoom (“PTZ”) camera with embedded active RFIDtransceiver; 2) Systems and methods for linking PTZ cameras to activeRFID transmissions to provide imagery of a RFID tagged object; 3)Systems and methods for providing simultaneous views of a RFID taggedobject's surrounding environment and a zoomed image of the taggedobject; 4) PTZ camera/s with embedded RFID antennas, receivers, and/orconditioning circuitry; 5) Mechanism/s and method/s for aligning a PTZcamera line of sight to a RFID tagged object (e.g., article, person,etc.); 6) Systems and methods for implementing anoperator-in-the-loop-based object location mechanism, and fordetermining validity of the location of an RFID tagged object; 7)Systems and methods for initiating a RFID tag transmission from a visualtracking camera (e.g., CCTV, etc.); 8) Methods and systems for luggageand passenger tracking in an airport or similar environment via the useof RFID tags; and 9) Methods and systems for factory alignment of anantenna array with the optical line of sight, e.g., the optical line ofsight of a PTZ camera attached to or otherwise integrated with theantenna ray.

In one respect, disclosed herein is a camera assembly unit including anoptical block and a RF receiver, the RF receiver being configured toreceive from an antenna an RF signal including a RFID broadcasttransmitted by a RFID device.

In another respect, disclosed herein is a camera assembly including anoptical block and at least one of an embedded RF receiver or an embeddedRF antenna. Where present, the embedded RF antenna may be configured toreceive a RFID broadcast transmitted by a RFID device. Where present,the embedded RF receiver may be configured to receive from a RF antennaa RF signal including a RFID broadcast transmitted by a RFID device.

In another respect, disclosed herein is a visual locating system,including a plurality of camera assemblies. Each of the cameraassemblies my include an optical block and a RF receiver, with the RFreceiver being configured to receive from a RF antenna one or more RFsignals including a RFID broadcast transmitted by a RFID device. Thesystem may also include a computer processor in communication with eachof the plurality of camera assemblies.

In another respect, disclosed herein is a method of locating objects ina passenger terminal, including associating a first RFID device with apassenger, and locating the passenger within the passenger terminalusing a RF transmission broadcast by the first RFID device. The methodmay also include tracking the passenger within the passenger terminalusing a visual locating system that includes a plurality of cameraassemblies. Each of the plurality of camera assemblies may include anoptical block and a RF receiver, with the RF receiver being configuredto receive from a RF antenna one or more RF signals including a RFIDbroadcast transmitted by the first RFID device. The system may alsoinclude a computer processor in communication with each of the pluralityof camera assemblies. The method may further include associating asecond RFID device with a luggage item or carry on item of thepassenger, and locating the luggage item within the luggage handlingareas of the passenger terminal (or locating the carry on item with thepassenger terminal) using a RF transmission broadcast by the second RFIDdevice.

In another respect, disclosed herein is a method of visually locatingobjects, including associating a RFID device with an object, andproviding a camera assembly unit including an optical block and a RFreceiver that is configured to receive from an antenna an RF signalincluding a RFID broadcast transmitted by the RFID device. The methodmay also include receiving a RFID broadcast transmitted by the RFIDdevice and received by the RF receiver from the antenna, and visuallylocating the object using the optical block of the camera assembly basedon the RFID broadcast received by the RF receiver from the antenna.

In another respect, disclosed herein is a method of aligning an opticalblock of a camera assembly with a RFID device, including providing acamera assembly unit including an optical block and a RF receiver, withthe RF receiver being configured to receive from an antenna an RF signalincluding a RFID broadcast transmitted by the RFID device. The methodmay also include receiving a RFID broadcast transmitted by a RFID deviceand received by the RF receiver from the antenna, and aligning theoptical block of the camera assembly with the RFID device based on theRFID broadcast received by the RF receiver from the antenna.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a passenger at an airport ticket counter where thedisclosed systems and methods may be implemented according to oneembodiment of the disclosed systems and methods.

FIG. 1B illustrates a RFID tag and associated ticket holder for tagginga passenger according to one embodiment of the disclosed systems andmethods.

FIG. 1C illustrates luggage tagged with RFID tags according to oneembodiment of the disclosed systems and methods.

FIG. 2 illustrates a located and highlighted passenger according to oneembodiment of the disclosed systems and methods.

FIG. 3 is a simplified illustration of a visual locating systemconfiguration according to one embodiment of the disclosed systems andmethods.

FIG. 4 is a flowchart of a method for visual tracking according to oneembodiment of the disclosed systems and methods.

FIG. 5 illustrates display of an RFID tagged article according to oneembodiment of the disclosed systems and methods.

FIG. 6 illustrates a camera assembly and RFID-tagged object according toone embodiment of the disclosed systems and methods.

FIG. 7A illustrates a signal processing circuitry according to oneembodiment of the disclosed systems and methods.

FIG. 7B illustrates summation of signals and summed signal strength as afunction of angular position according to one embodiment of thedisclosed systems and methods.

FIG. 8 illustrates a camera assembly and RFID-tagged object according toone embodiment of the disclosed systems and methods.

FIG. 9 illustrates an operator selection screen display according to oneembodiment of the disclosed systems and methods.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The disclosed systems and methods may be employed to RFID and/orvisually track objects in a variety of different applicationenvironments, for example, in asset tracking applications. Other exampleenvironments in which the disclosed locating systems and methods may beimplemented include, but are not limited to, tracking of personnel orother individuals. For example, one specific case is tracking passengersthrough an airport (or other passenger processing facility such as trainstation, passenger dock, etc.) in an exemplary manner as describedbelow.

FIG. 1A illustrates a passenger 100 during the check-in process at anairport ticket counter 102. During such a check-in process, passenger100 may receive ticket/boarding documents for a flight, and/or mayoptionally check luggage for the flight. Although FIG. 1A illustratesticket counter personnel 104 assisting passenger 102 withticket/boarding documents, it will be understood that the disclosedsystems and methods may also be implemented with automatic or un-mannedcheck-in systems in which ticket/boarding documents are automaticallydispensed to passenger 102, and/or luggage is automatically checked.

As shown in the exemplary embodiment of FIG. 1B, during passengercheck-in at the ticket counter or at any other suitable station (e.g.,at the airport entrance, at a security check-point, at the gate, etc.) aRFID tag or other suitable form of RFID device 110 may be placed in aRFID carrier such as a ticket holder 112 that is given to passenger 102and that is to remain with passenger 102 at least until passenger 102boards an aircraft (or other passenger vehicle such as train, ship,etc.). Alternatively, a RFID tag 110 may be placed in any other suitableform of RFID carrier (e.g., document, badge, etc.) that is given orassigned to passenger, or may be attached (e.g., permanently or ininseparable fashion) to the passenger's ticket itself. Furthermore,rather than placing a RFID into a ticket holder during the check-inprocess, it is also possible that a RFID tag may be present as anintegrated or pre-existing part of a RFID carrier, e.g., RFID that ismanufactured into a ticket holder jacket or ticket itself. In a furtherembodiment of the disclosed systems and methods illustrated in FIG. 1C,a passenger's checked luggage 120 may also be tagged with an RFID 110that is attached to or contained within any suitable form of RFIDcarrier 122. As illustrated in FIG. 1C, RFID carrier 122 may beconfigured to remain with luggage 120 (e.g., shown here as beingtransported on baggage cart 124) throughout the baggage handling processfrom origin to destination.

Once a passenger 100 and/or luggage 120 are tagged with RFID tags 110,they may be tracked throughout an airport, for example, using any methodor system that is suitable for tracking the location of RFID tags 110.Such methods and systems include, but are not limited to, embodiments ofRFID tracking methods and systems as described further herein. Forexample, one or more RFID detectors (e.g., in the form of RFID receiversand/or transceivers) may be configured (with or without associatedcameras) to determine and/or track the location of individual RFID tags110 throughout an airport. In one embodiment, RFID detectors (configuredwith or without associated cameras) distributed at locations throughoutan airport (e.g., at fixed locations in different rooms and/or at fixedlocations to cover different areas of the airport) may be employed tofollow the location of a passenger based on receipt of RFID signals fromthe passenger's RFID tag 110 by the different RFID detectors as thepassenger moves from the vicinity of one RFID detector to another. Insuch an implementation, a location history may be generated that recordsthe passenger's movements between rooms or areas of the airport.

In another embodiment, a passenger at an unknown location within theairport may be located in real time by searching the airport with RFIDtransmissions. In this regard, multiple RFID transmitters ortransceivers located throughout the airport may transmit RFID tagactivation data, and a passenger may be located in real time based onreceipt of RFID signals from the passenger's RFID tag 110 by one or moreRFID detectors (configured with or without associated cameras).Combinations of one or more such RFID location methods with visualtracking methods described further herein are also possible.Combinations of visual and non-visual RFID location methods are alsopossible. In this regard, non-visual (non-camera equipped) RFIDdetectors may be employed to locate or follow the location of apassenger within the airport under normal circumstances, and visual(camera equipped) RFID detectors employed to visually track or obtain animage of the passenger only when specifically needed.

In the practice of the disclosed systems and methods, a passenger 100and/or luggage 120 may be tracked throughout all or any given portion ofthe air transportation system using the RFID tags 110. In this regard,an airport-wide locating system may be implemented to track a passenger100 from check-in point to gate, and/or to track luggage 120 fromcheck-in point to an aircraft. Alternatively, using a multiple-airportlocating system may be implemented to track a passenger 100 fromcheck-in point at an origin airport to a selected arrival point at adestination airport (e.g., the gate, the luggage claim area, an exitportal from the airport, etc.). Similarly, a multiple-airport locatingsystem may be implemented to track luggage 120 from check-in point at anorigin airport to a selected arrival point at a destination airport(e.g., including in any of the luggage handling areas of the airport,the luggage claim area of the airport, an exit portal from the airport,etc.).

Location of a given RFID tag 110 may be communicated from a given RFIDdetector to one or more RFID tracking computer processor/s using anysuitable hardwire or wireless technology. A RFID tracking computerprocessor may in turn track and/or process the current location andlocation history of a given passenger or luggage RFID tag 110 in anysuitable manner including, but not limited to, by storing theinformation in memory, displaying real time location or location historyof each passenger luggage on an operator display, selectively displayingon an operator display the real time location or location history ofspecific passenger/s or luggage that have been selected for heightenedmonitoring, processing the location information to determine if a givenpassenger or luggage has entered an area that is unauthorized for thegiven passenger or luggage and initiating display of this information oran alarm, combinations of the preceding, etc.

It will be understood that a multiple airport locating system may beimplemented using geographically remote RFID tracking computersub-systems located at different airports, and that any network or othertype of communication system may be employed that is suitable forinterlinking geographically remote computer sub-systems. Furthermore, anRFID locating system may also be optionally implemented to trackpassenger 100 and/or luggage 120 while on an aircraft using RFIDtracking mechanisms and tracking computer subsystem/s installed on theaircraft. In such an exemplary embodiment, communication withground-based computer components of an RFID locating system may beaccomplished using any aircraft-based communication equipment suitablefor computer network communications, e.g., such as may be alreadyinstalled on the aircraft. In yet another exemplary embodiment, portableRFID tracking subsystems may be employed to allow “spot checks” ofpassengers 120 and/or luggage 120 boarded on an aircraft sitting on theground, or at any other location not accessible by an existing RFIDtracking subsystem. In such an exemplary embodiment, a portable RFIDtracking subsystem may be configured to communication with an RFIDtracking computer system using any suitable methodology, e.g., usingwireless computer networking technology, using hardware connectorprovided at a Jetbridge console or other suitable location, etc.).

In one exemplary embodiment, RFID tags 110 associated with a passenger100 and their respective luggage 120 may be linked in a RFID trackingcomputer system that tracks the RFID tags 110. Such an implementationmay be employed, for example, to monitor the location of a givenpassenger 100 relative to luggage 120 that is associated with the givenpassenger 120, e.g., to verify that the passenger 100 travels on thesame aircraft as does any luggage 120 checked by the passenger 120. Insuch a case, a RFID tracking computer system may be configured toautomatically detect or recognize that a given passenger 100 has beenseparated from their associated luggage 120, e.g., a passenger 100 hasnot boarded the same aircraft into which their associated luggage 120has been loaded. In another exemplary embodiment, a passenger's carry onitems may also be tagged with respective RFID tags 110 and linked to theRFID tag 110 associated with the passenger in a RFID tracking computersystem. Such an implementation may be employed, for example, to monitorthe location of a given passenger 100 relative to carry on item/s thatare associated with the given passenger 120, e.g., to verify that thepassenger 100 maintains the carry on item/s in their possession. In sucha case, a RFID tracking computer system may be configured toautomatically detect or recognize that a given passenger 100 has beenseparated from their carry on item/s, e.g., a passenger 100 has left thecarry on item/s unattended somewhere within the airport. This may bedone, for example, by locating said carry on item within said passengerterminal using a RF transmission broadcast by said first RFID device,and detecting when the location of the passenger differs from thelocation of the carry on luggage by a predetermined distance and/or fora predetermined length of time.

In a further embodiment, RFID passenger and/or luggage trackinginformation may be integrated with operational information, for example,so that legitimate reasons for separation of a given passenger 100 withtheir associate luggage 120 may be identified. Such legitimate reasonsmay include, for example, failure of a passenger 100 to make aconnection between two different flights, volunteering by a passenger100 to accept a voucher to miss an overbooked flight, etc. In oneexemplary implementation of such an embodiment, a RFID tracking computersystem may be in communication with airport and/or airline-maintainedoperational computer systems that track airline flight statusinformation (e.g., flight cancellations, flight arrival and departuretimes, aircraft maintenance delays, changes in specific aircraft usedfor a given flight, overbooked flights, aircraft standby lists, lists ofpassengers 100 that volunteer for vouchers on overbooked flights, etc.)to help identify legitimate reasons for passenger/luggage separation.

In yet another exemplary embodiment, a passenger 100 may be photographed(e.g., under suitable lighting conditions for the photographic equipmentemployed) while at the ticket counter or at any other suitable stationin the airport, for example, for facial recognition purposes and forverification at the gate. In this regard, a passenger 100 may be sophotographed in addition to (and optionally at the same time as) beingassigned or tagged with an RFID tag 110. In one exemplary implementationof such an embodiment, a gate or other security station may be equippedwith both a RFID reader (e.g., RFID receiver or transceiver) for readingthe passenger's RFID tag 110, and a display (e.g., LCD, CRT, etc.)linked to a central computer of a RFID computer locating system fordisplaying a passenger's photograph. The RFID computer locating systemmay then be so configured to automatically display to a gate attendantthe photograph of a given passenger 100 when the RFID tag associatedwith that given passenger is read at the gate (e.g., presented at thegate kiosk during passenger boarding). Display of a passenger'sphotograph at the gate may be advantageously implemented as analternative to requiring the passenger to re-present identification atthe gate kiosk.

It will be understood that the disclosed systems and methods may beimplemented using any type of RFID device technology having a rangesuitable for detection by one or more RFID detectors/RFID antennaapparatus of a given apparatus or system. In this regard, a RFID devicemay be configured to transmit a RFID broadcast response in response toan external stimulus received by the RFID device (e.g., such as RFIDactivation data transmitted by an RFID transmitter or transceiver),and/or may be configured to autonomously transmit a RFID broadcast(e.g., to transmit a RFID broadcast periodically or on a continuousbasis). Thus, it will be understood that the methods and systemsdescribed herein as employing RFID devices that respond to RFIDactivation data with an RFID response broadcast are exemplary only, andthat autonomously-transmitting RFID devices may also be suitablyemployed in the same methods to transmit a RFID broadcast for receptionby one or more RFID detectors without the need for RFID activation datatransmitted by an RFID transmitter or transceiver. It will also beunderstood that autonomously-transmitting RFID devices may also beemployed in combination with RFID activation data where RFID devicesthat respond to transmitted RFID activation data are also present in asystem, or where the autonomously-transmitting RFID devices are alsoconfigured to respond to transmitted RFID activation data.

In this regard, a RFID tag 110 may be a re-useable RFID tag, or may be adisposable (or one-use-only) RFID tag. For example, a particularre-useable RFID tag 110 may be activated and associated with a givenpassenger 100 at the ticket counter or other suitable stations and thenused to track the passenger throughout the airport until the passengersboards an aircraft. When a re-useable RFID tag 110 is scanned at thegate kiosk the associated passenger 100 may be noted by the RFIDtracking computer system as boarding the plane, and the RFID tag 110 maybe automatically deactivated or disassociated with the passenger 100.Further, as this passenger boards the aircraft at the gate, the gateattendant may recover the re-useable RFID tag 110 from the passenger 100(e.g., by taking the RFID tag 110 from the RFID container). Where aticket holder is employed as a RFID container for a re-useable RFID tag110, the gate attendant may remove the paper ticket from the ticketholder, give the paper ticket back to the passenger, and send the ticketholder with re-useable RFID tag 110 back to the ticket counter or othersuitable station for reuse. Alternatively, a particular re-useable RFIDtag 110 may remain with a given passenger 100 for the duration of thepassenger's flight itinerary, and then removed and deactivated when thepassenger 100 reaches their final destination. In a similar manner, aparticular re-useable RFID tag 110 that has been associated with a givenpiece of luggage 120 may be removed as the luggage is either placed onthe plane at the origin airport or as it is taken from the plane, orremoved from the airport at the final destination. In any case, thereusable RFID tag 110 may be deactivated or disassociated from the givenpiece of luggage 120 and reused. A similar methodology may be employedfor disposable RFID tags, with the exception that there is no need torecover a disposable RFID tag 110 upon deactivation or disassociationwith a given passenger 100 or piece of luggage 120.

In another exemplary embodiment illustrated in FIG. 2, the disclosedlocating systems and methods may be employed to visually locate aparticular passenger 100 in a cameral display 202 of an airportenvironment, e.g., among a large number of other passengers in a crowdedairport terminal. Such an embodiment may be implemented using a RFIDlocating system that employs pan-tilt-zoom (PTZ) cameras equipped withRFID antenna array, e.g., such as a RFID locating system described andillustrated with respect to FIGS. 3-10 herein. Such cameras may beoperatively configured at multiple locations within an airport andcoupled to a RFID locating system so as to provide the system with acombined visual field of view that covers substantially all areas of anairport, or that covers selected areas of an airport (e.g., ticketcounter, security checkpoint, gate area, baggage claim area, etc.).

If at any time a given passenger 100 needs to be visually located,information from the RFID tag 110 associated with the given passenger100 may be used to identify which PTZ camera has the given passenger 100within its field of view. Where continuous RFID tracking is employed,this information may be retrieved from the location history maintainedin system memory for the given passenger 100. Otherwise, the antennaarrays of the system PTZ cameras so equipped may be activated to locatethe particular RFID tag 110 associated with the given passenger 100. Ineither case, an appropriate PTZ camera having the given passenger 100within its field of view may be identified and a display 202 generated(e.g., for an operator) that shows the area within which the givenpassenger 100 is located. The operator may then manually direct the PTZcamera in such a way as to zoom-in and focus on the given passenger 100,and/or the PTZ camera may automatically zoom-in and focus on the givenpassenger 100 using its RFID antenna arrays and the transmissions of theparticular RFID tag 110 associated with the given passenger 100, forexample, in a manner as described further in relation to FIGS. 3-10herein.

In those embodiments where a given passenger 100 has been digitallyphotographed (e.g., at the ticket counter or other suitable station),then face recognition methodology may be used to further locate orpinpoint (e.g., highlight) the passenger 100 within the display area 202(as indicated by the highlighted box 204 in FIG. 2) prior to zooming inon the passenger 100, i.e., assuming that the camera has a view of thegiven passenger's face. As previously described herein, if carry onluggage is also tagged then the relationship between the passenger andtheir luggage may be discerned at any time. These are just a few of theexemplary tasks, and combinations thereof, that may be performed usingthe disclosed visual locating systems and methods.

FIG. 3 illustrates one exemplary embodiment of a wide area multi-cameravisual locating system 300 having multiple visual tracking PTZtelevision camera assemblies 302 (shown in FIG. 3 to be configured withoptional dome enclosures), which may be configured with differentialantenna arrays in a manner as described elsewhere herein. In theembodiment of FIG. 3, multiple camera assemblies 302 are showncommunicatively coupled together and communicatively coupled to acomputer processor 310 via hardwire 314 (e.g., a local area network“LAN” or any other suitable hardwire communication method) to form thewide area multi-camera visual locating system. It will be understoodthat in other embodiments multiple camera assemblies 302 may becommunicatively coupled together and/or communicatively coupled to acomputer processor 310 via wireless communication methods (e.g.,wireless network, etc.).

Although exemplary PTZ television cameras are described and illustratedherein, it will be understood that benefits of the disclosed systems andmethods may be realized using any camera configuration suitable forproviding a suitable field of view and/or suitable visual representationof the viewed area that is desired or needed for a given application.Examples of types of cameras that may be employed include, but are notlimited to, non-articulated cameras, cameras that are articulated inonly one plane, cameras that may be articulated in multiple planes, etc.Furthermore, one or more cameras for generating any type of visualrepresentation of a given area that is suitable for the needs of a givenapplication may be may be employed including, but not limited to,infra-red cameras, thermal imaging cameras, radiation imaging cameras,etc. It will also be understood that any desired number of one or morecameras (e.g., a single camera, more than four cameras, less than fourcameras, etc.) may be employed, and that multiple cameras may beselectively positioned in remote relationship to each other (e.g., toprovide views of different rooms, to provide views of different areas ofthe same room, to provide views of both inside and outside areas of abuilding, etc.)

FIG. 3 also illustrates other exemplary components that may be employedas part of a visual locating system 300. As shown, these components mayinclude one or more computer processors 310 (e.g., PC or other suitablecomputing device) that may be communicatively coupled to a network ofPTZ television camera assemblies 302 via hardwire 314 (as shown) or byany other suitable method, e.g., wireless interconnect. In theillustrated exemplary embodiment, RFID receivers 304 may be configuredas a part of each respective PTZ television camera assembly 302 having adifferential antenna array. Also shown in FIG. 3 are optional imageprocessing and camera control units 312 that may be coupled betweencomputer processor/s 310 and each PTZ television camera assembly 302 viahardwire 316 (or alternately by wireless link). In this regard, optionalimage processing and camera control units 312 may include digital signalprocessing (“DSP”) circuitry, hard drive, etc. that may be present toperform image processing and/or camera control tasks). However, it willbe understood that computer processor/s 310 may be directly coupled tocamera assemblies 302 without the presence of optional image processingand camera control units 312 therebetween.

Still referring to FIG. 3, one or more stationary wide area RFIDtransceivers 315 (e.g., of the type available from Active Wave, Inc. ofBoca Raton, Fla. or other suitable supplier) may be located throughoutan area of concern (e.g., in different rooms of building, in differentareas of a room, etc.) in any pattern suitable for achievingcommunication coverage as desired or needed for a given application. Inthis regard, stationary wide area RFID transceivers 315 may bepre-existing components of a conventional RFID installation, or may beinstalled contemporaneously with other components of the disclosedsystems and methods. Computer processor/s 310 may be communicativelycoupled to stationary wide area RFID transceivers 315 via wirelesscommunication link 317 as shown, or by any other suitable method, e.g.,by hardwire. In this regard, a computer processor 310 may be coupled toone or more local or remote transmitters and/or antenna elementssuitably configured for communicating with one or more stationary widearea RFID transceivers 315 to fit the needs or requirements of a givenapplication. In one exemplary embodiment, computer processor/s 310 maybe configured with transmitters and antenna elements that are arrangedor configured in such a way as to cover a narrow or smaller RFtransmission area than a larger RF transmission area covered bystationary wide area RFID transceivers 315, but at the same time so thatall stationary wide area RFID transceivers 315 are in communication withthe system via the transmitters of computer processor/s 310.

In one exemplary embodiment, a given RFID tag 110 of FIG. 3 may belocated as follows. A query in the form of RFID tag activation data(e.g., RFID key number or other suitable tag identifier information)corresponding to the given RFID tag 110 may be entered into computerprocessor 310 (e.g., manually entered query, automatic query entered byanother computer system or computer processor coupled to computerprocessor 310, etc.). Computer processor 310 may then wirelesslytransmit at a first frequency interrogation data in the form of the RFIDtag activation data to each of stationary wide area RFID transceivers315 via wireless link 317. Stationary wide area RFID transceivers 315may then rebroadcast the interrogation data over a larger area viawireless communication link 319 on a second and different frequency(that is receivable by RFID tags 110) from the first frequency. Inresponse to the tag activation data of the interrogation data receivedfrom one or more of stationary wide area RFID transceivers 315, only onegiven RFID tag 110 within the radio frequency (RF) transmission range ofthe stationary wide area RFID transceivers 315 will respond and send outan acknowledge broadcast 321 that may be received by one or more of RFIDreceivers 304 (e.g., via differential antenna arrays of cameraassemblies 302).

In a manner that will be described further herein, a broadcast responsereceived from a given RFID tag 110 may be received by one or more ofantenna-equipped PTZ camera assemblies 302 that may in turn communicateRFID tag response information (e.g., responding RFID tag ID, signalstrength of RFID response, etc.) to computer processor 310 via hardwirecomponents 316, 312, 314 (or alternately by wireless link). Based onthis RFID tag response information, computer processor 310 may recognizethat a particular RFID tag 110 has responded and may optionally takefurther action to locate or further define the location of theresponding RFID tag 110 by further processing the RFID tag responseinformation. For example, computer processor 310 may optionally verifythat each response was received from the desired RFID tag 110 and/or mayselect one or more camera assemblies 302 that received the strongestRFID response signals from tag 110 for further visual scanning action.Computer processor may then communicate scanning commands to theselected camera assemblies via hardwire components 316, 312, 314 (oralternately by wireless link). Each of the selected camera assemblies302 may then scan an area based on the location of the response receivedby the respective camera assembly 302 from the given RFID tag 110.

Visual scanning information from each of the selected camera assemblies302 may then be communicated back to computer processor 310 via hardwirecomponents 316, 312, 314 (or alternately by wireless link), which maysimply display the results to an operator, or which may further processthe visual scanning results and/or take further action based thereupon.For example, computer processor 310 may evaluate the quality of thevisual scanning results received from each selected camera assembly 302,e.g., based on one or more factors such as RFID signal strength, RFIDsignal quality, etc. In this regard, RFID signal quality may beevaluated, for example, using a checksum method to verify quality of theRFID signal versus random noise. Computer processor 310 may then selectimages from one or more of selected camera assemblies 302 for viewing,and/or may communicate additional scanning commands to one or morecamera assemblies 302 (e.g., wider or narrow scan areas, re-scan withcamera lens zoomed in or out, etc.). In this regard, computer processor310 may be optionally configured to communicate with camera assemblies302 so as to interactively repeat and refine visual scans prior todisplay to an operator.

FIG. 4 depicts a flow chart showing one exemplary embodiment of a methodof using the visual locating system 300 of FIG. 3 to locate anRFID-tagged object and to display view/s of the object to a systemoperator. At step 402, an operator keys in RFID tag identifierinformation (e.g.,. RFID key code) at computer processor 310, which maybe a PC or PC work station. At step 404, the RFID identifier code isthen communicated wirelessly or via hardwire to stationary wide areaRFID transceivers 315. At step 406, stationary wide area RFIDtransceivers 315 re-broadcast the RFID identifier information at afrequency receivable by the RFID tags 110 of the system 300, and at step408 the particular RFID tag 110 that corresponds to the transmitted RFIDidentifier information reacts to the identifier information by emittinga signal/s at the RFID frequency. At step 410, one or more of the RFIDreceivers 304 of camera assemblies 302 detect and receive the signal/semitted by the particular RFID tag 110. At step 412, the signal strengthof the RFID tag signals received by each camera assembly is thencommunicated back to computer processor 310 via hardwire components 316,312, 314 (or alternately by wireless link). A software applicationrunning on computer processor 310 processes the signal strengthinformation at step 414 to determine and select the camera assembly orcamera assemblies 302 receiving the strongest RFID response signals(e.g., those camera assemblies 302 receiving a signal exceeding aparticular pre-defined signal strength value), and at step 416communicates scan commands via hardwire components 316, 312, 314 (oralternately by wireless link) back to the camera assemblies 302 selectedin step 414.

At step 418, each of the camera assemblies 302 that were selected instep 414 respond to the scan commands issued by computer processor 310by scanning (i.e., panning and tilting) through their full range ofmotion while receiving RFID response signal emissions from theparticular RFID tag 110 that was activated by the previous transmissionof RFID identifier information in step 406. Each selected cameraassembly 302 employs a differential antenna array and signal processingto choose one or more best camera position solutions that are likely tocorrespond to a camera position at which the camera LOS is substantiallyaligned with the responding RFID tag 110. For each best camera positionsolution, each camera assembly 302 retains in memory visual image datacorresponding to that position.

At step 420, each camera assembly 302 evaluates whether scanningoperations have completed prior to cessation of broadcast by aresponding RFID tag 110. If a responding RFID tag 110 has ceasedtransmission prior to completion of the scan, then the RFID identifiercode of the particular RFID tag 110 may be rebroadcast by stationarywide area RFID transceivers 315 (e.g., rebroadcast of RFID identifiercode may be coordinated by computer processor 310 upon receipt ofinformation concerning lack of complete scan from one or more cameraassemblies 302). In yet another alternatively embodiment, computerprocessor 310 may evaluate whether scanning operations have beencompleted by all of the selected camera assemblies 302 prior tocessation of broadcast by a responding RFID tag 110 (e.g., by trackingstatus of scanning responses received from the selected cameraassemblies 302), and may trigger rebroadcast of RFID identifier code inthe event it determines that scanning operations have not been socompleted.

When each camera assembly 302 that was selected in step 414 determinesin step 420 that its scanning operations have been completed, itcommunicates in step 424 the scan results (e.g., signal strength versuscamera position, number and relative signal strength experienced duringeach scan, etc.) and visual image data associated with the scan resultsthat has been stored in memory to computer processor 310. In step 426,computer software running on computer processor 310 selects the topscanning solution/s based on signal strength (e.g., comparison of signalstrength to a minimum signal strength threshold) and optional resultfactor/s (e.g., signal quality). The selected top scanning solution/sthat meet signal strength and result quality factor criteria are thencommunicated to an operator. One or more visual images associated withthe selected top scanning solutions are also communicated to an operatorvia suitable visual display in step 428.

In step 430, an operator may select a visual image (e.g., from a set ofvisual images corresponding to the selected top scanning solutions ofstep 428) for further display by, for example, input to a graphical userinterface (GUI) such as described further herein in relation to FIG. 9,or by other suitable methodology. In response to the operator selection,computer processor 310 may display zoomed and non-zoomed versions of aselected visual image in step 432, for example, using methodologydescribed further herein in relation to FIG. 5. If the selected image isacceptable to the operator (e.g., selected image corresponds to thedesired RFID-tagged object being sought), then the operator may acceptthe result in step 434, and subsequent action taken as appropriate instep 438 (e.g., retrieve object, further examine the object, statusand/or location of the object noted, etc.). However, if the selectedimage is not acceptable to the operator (e.g., selected image isindeterminate or does not correspond to the desired RFID-tagged objectbeing sought), then the operator may reject the result in step 434, inwhich case a new set of visual images is displayed in step 436 thatcorresponds to the selected top scanning solutions of step 428 minus therejected visual image of step 434. At this point, the operator repeatsstep 430 by selecting a visual image from the new set of top scanningsolutions of step 436, and steps 432, 434, 436 and 430 are repeated asnecessary until step 438 is reached.

It will be understood that the exemplary embodiments of FIGS. 3 and 4represent just one example visual locating system topology and method ofuse thereof that may be employed in the practice of the disclosedsystems and methods. It will be understood that a PC or other suitablecomputer processor 310 may be hardwired to one or more stationary widearea RFID transceivers 315, or computer processor 310 may be in wirelesscommunication with stationary wide area RFID transceivers 315 using aseparate computer processor base station transceiver (not shown). Itwill also be understood that any electronic communication protocol/ssuitable for accomplishing communication between the separate componentsof a visual locating system may be employed.

In an another embodiment, RFID transceivers may be embedded in a cameraassembly, such as camera assemblies 302 of FIG. 3, in addition to or asan alternative to stationary wide area RFID transceivers 315. In such anembodiment, an RFID tag interrogation process by a transceiver embeddedin a camera assembly may be initiated via a network connection, e.g.,via a LAN connection coupled between LAN based camera assemblies 302such as hardwire components 316, 312, 314 (or alternately by wirelesslink). In a LAN-based camera assembly network embodiment, transceiverpower may be obtained from the camera power supply. When so employed,transceivers embedded in the visual tracking PTZ cameras 302 offer theadvantage of simplifying the installation effort, e.g., by eliminatingthe need to install separate transceivers (e.g., stationary wide areaRFID transceivers 315) into the walls or other parts of a building andto provide power to the same via batteries or separate power supplylines. Thus, as used herein with reference to a camera assembly havingone or more embedded devices (e.g., receiver, transceiver, antennaelement, antenna array, signal processing circuitry, digital signalprocessor, etc.), it will be understood that the term “embedded” meansthat the given device/s are physically coupled to other components ofthe camera assembly so as to form a camera assembly unit or module thatcontains the given device/s.

In yet another embodiment, one or more computer processors may becommunicatively coupled to a network of first stage transceivers viahardwire or by any other suitable method, e.g., wireless interconnectthat may communicate with embedded second stage transceivers that areconfigured as a part of PTZ television camera assemblies havingdifferential antenna arrays. The network of first stage transceivers maybe located in any pattern suitable for achieving communication coveragewith the embedded second stage transceivers of the PTZ television cameraassemblies as desired or needed for a given application. In oneexemplary embodiment, the first stage transceivers may be arranged orconfigured as a network of intermediate transceivers in such a way as tocover a narrow or smaller area than a wide or larger area covered by thenetwork of second stage transceivers, but at the same time so that allsecond stage transceivers are in communication with the system via thenetwork of intermediate first stage transceivers.

Whether communicated via hardwire or wireless communication link, aquery in the form of RFID tag activation data may be entered into thecomputer processor, which then may then communicate interrogation datain the form of the RFID tag activation data to the camera assemblies.Embedded RFID transceivers in the camera assemblies may then rebroadcastthe interrogation data, e.g., via differential antenna arrays mounted onthe camera assemblies. In response to the tag activation data receivedfrom one or more of the embedded RFID transceivers, only one given RFIDtag within the radio frequency (RF) transmission range of the network ofcamera assemblies will respond and send out an acknowledge broadcastthat may be received by one or more of the embedded RFID transceivers(e.g., via differential antenna arrays of the camera assemblies), and inturn communicated as RFID tag response information (e.g., respondingRFID tag ID, signal strength of RFID response, etc.) to the computerprocessor via RF broadcast or hardwire depending on the networkconfiguration. Further processing (e.g., refining the location of theresponding RFID tag, further RFID scanning, visual scanning, display ofvisual scanning results, etc.) may be performed as previously describedin relation to FIGS. 3 and 4.

In one exemplary embodiment, an object may be located using thedisclosed methods and systems for visual tracking, and as shown in FIG.5, both the object's surroundings 500 and a digitally zoomed image 502of the object may be simultaneously displayed (e.g., on a single displayusing window-in-window views, or on separate displays). Such anembodiment may be advantageously implemented, for example, byconfiguring visual tracking camera assemblies 312 of FIG. 3 with highresolution digital PTZ cameras. The dual view display may beadvantageously employed (e.g., in steps 432 and/or 438 of the embodimentof FIG. 4, or in other alternate embodiments) to allow for verificationof the condition of the displayed object, while at the same timeallowing for a full description or depiction of where the object is.Maintaining the overall view of the object's surroundings allows for asystem operator to guide a fellow worker (e.g., via cell phone,walkie-talkie, etc.) to the exact location efficiently. Alternatively oradditionally, each camera view (whether a single view of the object ordual view of the object and its surroundings) may be labeled with theidentity of the camera (and/or the area being displayed) to assist theoperator in identifying the location of the object.

As previously described, training or calibration of the disclosed visuallocating systems is not required. However, training or calibration maybe optionally used to further enhance the system accuracy and reduce thenumber of preliminary views presented to an operator, e.g., viatriangulation of the object based on delay calculations on the receivedtag transmission, or other suitable method.

FIG. 6 illustrates one exemplary embodiment of a PTZ camera assembly 600as it may be implemented to track and/or locate an object 620 having aRFID tag 110 attached thereto. As illustrated in FIG. 6, PTZ cameraassembly 600 includes camera assembly base member 610 that is coupled tocamera support member or yoke 604 by camera assembly base brackets 612.Camera support member 604 is in turn coupled to camera optics or opticalblock 602 in the manner shown so as to provide a pivot point 606 foroptical block 602 and so that light or image-gathering lens 603 ofoptical block 602 is disposed in position to receive an image of object620. Camera optical block 602 may include any combination of opticalcomponents (e.g., lenses, focus and/or zoom drive mechanisms, prismsand/or mirrors, etc.) and electronic components (e.g., image sensor/s)that is suitable for capturing a visual image (e.g., photographic orvideo image, infra-red image, thermal image, radiation image, etc.) inelectronic form.

As shown, camera support member 604 may be rotatably mounted to basebrackets 612 so that member 604 may be employed to controllably rotateor tilt optical block 602 in the directional plane indicated by arrow650 of FIG. 6 using drive mechanism 608 (e.g., standard brushless DCelectric motor and/or associated gear box) that is operatively coupledto support member 604. Camera assembly 600 may be coupled to astationary member (e.g., wall, ceiling or other suitable structuralmember) by a rotatable assembly (not shown) so that camera assembly basemember 610 may also be rotated so that base member may be employed tocontrollably rotate or pan optical block 602 in the directional planeindicated by arrow 652 of FIG. 6 using a suitable drive mechanism (alsonot shown). Although not shown, camera assembly 600 may be optionallycontained within a spherical or semispherical camera assembly domeenclosure or other suitable enclosure.

FIG. 6 illustrates just one exemplary embodiment of the manner in whicha camera optical block may be configured and movably mounted as part ofa PTZ camera assembly employed in the practice of the disclosed systemsand methods. In this regard, it will be understood that a camera opticalblock may have a single linear optical path, or may be configured withother geometries, e.g., folded light path optical block. A cameraoptical block may also be mounted using any other configuration ofstructural members and/or drive mechanisms suitable for controllablyrotating an optical block in one or more directional planes, includingusing conventional PTZ camera drive mechanisms or any other combinationsof drive and/or rotation mechanisms suitable for rotating a cameraoptical block about one or more rotational axes.

Examples of camera optical block configurations (e.g., folded opticalblocks) and mechanisms for mounting and/or drive mechanisms for movingcamera optical blocks as part of a camera assembly that may be employedin the practice of the disclosed systems and methods may be found, forexample, in concurrently filed U.S. patent application Ser. No.10/732,195, entitled “Electromagnetic Circuit And Servo Mechanism ForArticulated Cameras”, by Thao D. Hovanky et al., in concurrently filedU.S. patent application Ser. No. 10/732,924, entitled “Slip RingApparatus”, by Richard G. Washington and Thao D. Hovanky, and in U.S.patent application Ser. No. 10/732,193, entitled “Optical BlockAssembly”, by Thao D. Hovanky and Richard G. Washington, each of theforegoing patent applications being incorprated herein by reference.Examples of other methods and mechanisms that may also be implementedwith camera assemblies in the practice of the disclosed systems andmethods may be found, for example, in concurrently filed U.S. patentapplication Ser. No. 10/732,740, entitled “Systems And Methods ForActuating Lens Assemblies”, by Thao D. Hovanky, and in concurrentlyfiled U.S. patent application Ser. No. 10/732,192 entitled “ThermallyCooled Imaging Apparatus”, by Richard G. Washington and Thao D. Hovanky,each of the foregoing patent applications being incorporated herein byreference.

Still referring to the exemplary embodiment of FIG. 6, camera assembly600 also includes a differential antenna apparatus in the form of adifferential antenna array 621 coupled to associated electronics thatmay include embedded or integrated RFID receiver circuitry 605 that maybe physically coupled to other components of camera assembly 600 asillustrated, or in other suitable manner and/or location. Differentialantenna array 621 includes four RFID antennas 622 that are mounted oneach side, above, and below the optical block 602 in symmetricalfashion, in this case in a position adjacent light or image-gatheringlens 603. Each of RFID antennas 622 is shown coupled to optical block602 by mounting pads 624 that extend outwardly from optical block 602,and are shown oriented in manner to allow reception of RFID signals fromthe same direction that light is received by lens 603. Such aconfiguration may be employed, for example, to allow for a closealignment of the antennas 622 with the optical line of sight (LOS) ofoptical block 602. In the illustrated exemplary embodiment of FIG. 6, afirst pair of RFID antennas 622 a located above and below the opticsblock are cooperatively employed together for vertical alignmentpurposes (e.g., in the tilt axis direction of arrow 650) and a secondpair of RFID antennas 622 b located on each side of the optics block arecooperatively employed together for horizontal alignment purposes (e.g.,in the pan axis direction of arrow 652). In one exemplary embodiment,rotation in the pan axis direction may be, for example, rotation of theassembly about a vertical axis, and rotation in the tilt axis directionmay be, for example, rotation of the assembly about a horizontal axis.

In the practice of the disclosed systems and methods, a differentialantenna apparatus may be configured with any type or combination oftypes of one or more antennas, directional antennas, antenna arrays, orother devices or combinations thereof suitable for directionallyreceiving electromagnetic radiation, such as RF signals from a RFID tag.In one embodiment, examples of suitable RFID antenna devices that may beemployed in the practice of the disclosed systems and methods include,but are not limited to, printed circuit board-based antenna devices,wire-based antenna devices, grid rod antenna devices, etc. availablefrom suppliers such as Texas Instruments of Plano, Tex. and Active Wave,Inc. of Boca Raton, Fla. Such antenna devices may be designed and/orconfigured to fit the needs of a given application based on a number ofconsiderations including, but not limited to, form factor size of agiven application, electromagnetic environment of a given application(e.g., metal in the installation area, shielding around the cameraoptical block, metal in the optical block and other camera assemblycomponents, space between the antenna elements), etc.

Furthermore, it will be understood that FIG. 6 illustrates just oneexemplary configuration of differential antenna array that may beemployed in the practice of the disclosed systems and methods, and thatany other differential antenna array configuration suitable foralignment of a camera optics block in one or more axis may be employed,e.g., including antenna arrays having more than four RFID antennas,antenna arrays having less than four RFID antennas, antenna arrayshaving RFID antennas located in positions other than vertically aboveand below and horizontally to either side of the optics block, andantenna arrays having RFID antennas located in positions other thanadjacent a light or image-gathering lens of an optical block. In thisregard, a differential antenna array may be directionally aligned with acamera optical block by configuring multiple directional RFID antennasin any position and/or manner to allow reception of RFID signals fromthe same direction that light is received by a light or image-gatheringlens of the optical block, and so that a directional line of receptionof the differential antenna array moves in a manner cooperatively withmovement of the LOS of the optical block, whether in a mannerproportionately or not thereto. Thus, a differential antenna array maybe operatively coupled to an optical block at a location other thansymmetrically adjacent the image or light gathering lens of the opticalblock (e.g., multiple antennas coupled symmetrically around the imagesensor end of the optical block, a symmetrical array of antennas coupledto extend from one side of the optical block, etc.), may be coupled to astructural member or other part of the camera assembly that moves withan optical block, may be coupled to a structural member that is not partof the camera assembly but that moves with an optical block, etc.

It will be understood that a differential antenna apparatus, such asdifferential antenna array 621 illustrated in FIG. 6, may be optionallycoupled to an embedded transmitter or transceiver component of a cameraassembly for transmitting RFID identifier information to RFID tags 110,e.g., in a manner as previously described herein. In this regard, all oronly a portion of the antennas or antenna elements of a differentialantenna array may be utilized for RFID transmission purposes, forexample, depending on the gain desired. Alternatively, a differentantenna array (differential or non-differential/non-directional) may beemployed for transmitting RFID identification information from anembedded RFID transceiver. For example, a separate 360° broadcastantenna may be configured in a camera assembly base member for RFIDtransmitting use by an transmitter or transceiver embedded in the cameraassembly.

In one embodiment of the disclosed systems and methods, respectivesignals from multiple RFID antennas may be coupled to any signalconditioning/processing circuitry suitably configured to create one ormore output signals related to or based on overall signal strengthand/or differential signal strength. For example referring to theexemplary embodiment of FIG. 7A, the first pair of RFID antennas 622 aof FIG. 6 may be coupled to provide received RF signals 710 and 712 tothe exemplary signal processing electronics circuit 700 as shown. Asillustrated, the signal processing electronics circuit 700 of FIG. 7 mayinclude, but are not limited to, RF amplifiers 714 and 716 and narrowband filters 718 and 720 (shown respectively coupled to each RFIDantenna 622 a). Also shown included in signal processing electronics 700are first summation circuit block 722 and second summation circuit block724, with delay block 726 coupled therebetween as shown.

Although not illustrated, it will be understood that the second pair ofRFID antennas 622 b may be similarly coupled to a second signalprocessing circuit having the same configuration as first signalprocessing circuit 700, e.g., for horizontal alignment purposes. Thus,for purposes of illustration, FIG. 7A shows the first pair of RFIDantennas 622 a of FIG. 6 coupled to a first signal processing circuit700, e.g. for vertical alignment purposes, it being understood that aseparate signal processing circuit channel 700 may be provided for eachrespective pair of RFID antennas 622 a and 622 b of FIG. 6 (i.e., avertical channel for RFID antennas 622 a positioned above and below theoptics block 621, and a horizontal channel for RFID antennas 622 bpositioned to each side of the optics block 621). In this regard, FIG. 7illustrates an exemplary signal processing electronics circuit channelthat may be employed for either one of the vertical or horizontal signalprocessing circuit channels, with a separate signal processing circuitchannel being provided for each.

Still referring to FIGS. 6 and 7A, when an activated RFID tag 110transmits a broadcast response 651, first and second antenna pairs 622 aand 622 b of camera assembly 600 each receive the broadcast response651, and in response thereto each antenna pair 622 a and 622 b providesRF signals to the respective signal processing electronics coupled tothe given antenna pair. For example, as shown in FIG. 7A, first antennapair 622 a provides RF signals 710 and 712 to respective RF amplifiers714 and 716 for signal amplification. Amplified RF signals 730 and 732are then provided to respective narrow band filters 718 and 720, whichoutput respective filtered signals 734 and 736. Signals 734 and 736 arein turn summed in first summation circuit block 722 to produce a summedsignal 740 indicative of the strength of the RF signal received byantenna pair 622 a. Signal strength signal 740 may be optionallycombined with a similar signal strength signal from processingelectronics coupled to antenna pair 622 b and the resulting combinedsignal used as a measure of the received RFID signal strength at thelocation of the given camera assembly 600. In alternative embodiments,any given one or more combinations of RFID signals received by multipleantennas of a differential antenna array 621 (e.g., summed signal 740 oreither one of un-summed signals 734 or 736) may be used as a measure ofreceived RFID signal strength. As described in relation to steps 412 and414 of the exemplary embodiment of FIG. 4, received RFID signal strengthmay be provided to a computer processor 310 and used to determine andselect one or more camera assemblies receiving the strongest RFIDresponse signals.

As illustrated in FIG. 7A, delay circuitry 726 may be used to delayfiltered signal 736 corresponding to a first one of antennas 622 arelative to filtered signal 734 corresponding to a second one ofantennas 622 a. In this regard, delay circuitry 726 may be configured toreceive signal 736 and to produce a delayed signal 738 that is delayedrelative to signal 736 by, for example, a delay factor of about 180°.Delayed signal 738 may then be summed with undelayed signal 736 insecond summation circuit block 724 to produce differential output signal742.

In one exemplary embodiment, all or a portion of signal processingcircuitry 700 may be integrated with or otherwise configured as a partof camera assembly 600, e.g., structurally attached to or integratedwith optical block 602 and/or differential antenna array 621, containedin camera assembly base member 610, etc. However, it is also possiblethat all or a portion of signal processing circuitry 700 may beoperatively disposed or positioned in any other suitable location, e.g.,contained in housing that is separate from camera assembly 600 andphysically positioned adjacent to or remote to camera assembly housing600. In any case, both the differential output signal 742 and signalstrength signal 740 outputs shown may be demodulated and fed into highspeed A/D converters (not shown). The outputs of these A/D convertersmay then provided to an onboard or offboard digital signal processor(“DSP”) (also not shown) for final processing in a manner as describedfurther herein (e.g., building and/or processing a lookup table ofoptical block position versus corresponding values of signal strengthsignal 740 and differential output signal 742 received from separatesignal processing circuitry 700).

FIG. 7B shows summed signal strength magnitude of differential outputsignal 742 relative to angular position of camera 600. As shown in plot700 of FIG. 7B, with a delay factor of 180° the magnitude of the summedsignal strength of differential output signal 742 reaches a null point(or minimum absolute value) when filtered signals 734 and 736 have thesame magnitude, i.e., when the vertical angular position of differentialantenna array is such that each of the two antennas 622 a are positionedat an equal distance from transmitting RFID tag 110, indicatingalignment of the LOS of optical block 602 of camera assembly 600 withthe transmitting RFID tag 110. It will be understood that any otherdelay factor (e.g., greater or lesser than about 180°) may be employedthat is suitable for producing a summed signal strength indicative ofvertical angular position of the LOS of optical block 602.

It will be understood that FIGS. 7A and 7B illustrate just one exemplaryembodiment of signal processing circuitry and methodology that may beemployed in the practice of the disclosed systems and methods. In thisregard, one or more of the particular illustrated circuit components ofsignal processing circuitry 700 (e.g., RF amplifiers, narrow bandfilters, delay circuitry, summation circuit blocks, etc.) may be absentor may be supplemented by additional similar or different components inany other combination suitable for measuring received RFID signalstrength and for indicating alignment of LOS of optical block 602 with atransmitting RFID tag 110. Furthermore, it will be understood that anyalternative signal processing methodology and/or circuitry may beemployed that is suitable for measuring received RFID signal strength ata camera assembly, and/or for using one or more directional antennaelements or antenna element arrays to align the LOS of a camera opticalblock with a transmitting RFID tag. For example, two or more antennaelements may be configured non-symmetrically around the LOS of a camerablock and/or the signals received by separate antenna elements of anantenna array may be processed through a separate analog to digitalconverter (“ADC”) and then provided to a digital signal processor(“DSP”) for processing using digital summation, subtraction and delayfunctions to align the LOS of the camera optical block with atransmitting RFID tag.

In one exemplary embodiment, a suitable processor (e.g., DSP,microprocessor or microcontroller, etc.) may build a lookup table ofoptical block position versus corresponding signal strength anddifferential output signal values. This may be done for each axis inwhich the camera assembly optical block rotates (e.g., once for rotationin a horizontal pan axis, and once for rotation in a vertical tiltaxis). The processor may eliminate or “weed out” null point values thatcorrespond to zero signal strength values for the same optical blockposition. The processor may also optionally eliminate null point valuesthat correspond to signal strength values that do not meet a selectedminimum signal strength value for the same optical block position. Theprocess of rotating the camera assembly optical block through each axisof rotation and building a corresponding table of optical block positionversus corresponding signal strength and differential output signalvalues may be controlled by the same processor and/or repeated as manytimes as necessary until suitable null point values are determined foreach axis.

A processor (e.g., DSP, microprocessor or microcontroller, etc.)responsible for building and processing a lookup table of optical blockposition versus corresponding signal strength and differential outputsignal values may be embedded in the camera assembly or may be locatedoffboard or external to the camera assembly. It is also possible thatone or more of the above-described tasks (e.g., determining signalstrength and differential output signal values, building a table ofthese values, eliminating values corresponding to zero and/or relativelylow signal strength, selecting null point position/s, controlling camerasweep operation, etc.) may be performed by more than one processor. Insuch a case, multiple processors may be integrated or embedded in thecamera assembly to perform these tasks (e.g. servo control DSP providedon camera assembly for controlling camera rotation, and secondaryprocessor provided on camera assembly for performing null pointidentification), one or more of the multiple processors may be embeddedand one or more of the other processors may be located remote oroffboard to the camera assembly, or all of the processors may be locatedremote or offboard to the camera assembly.

In one exemplary embodiment, a servo control DSP embedded in a cameraassembly may build and process a lookup table of optical block positionversus corresponding signal strength and differential output signalvalues. In another exemplary embodiment, a co-processor embedded in acamera assembly separate from a servo control DSP may build and processa lookup table of optical block position versus corresponding signalstrength and differential output signal values. In another exemplaryembodiment, an offboard processor that is remote from the cameraassembly (e.g., computer processor 310 of system 300 of FIG. 3 may buildand process a lookup table of optical block position versuscorresponding signal strength and differential output signal values.

In one embodiment, a network of multiple PTZ camera assemblies 600 maybe deployed as part of a visual locating system, such as visual locatingsystem 300 of FIG. 3. When a RFID tag 110 is initially activated and itsbroadcast response detected by one or more receivers of the visuallocating system, all or a given portion of the camera assemblies 600 onthe network of the visual locating system may be employed to determinethe signal strength at their specific location. In this regard, allcamera assemblies 600 may be activated to make the signal strengthdetermination, or alternatively only those camera assemblies 600receiving a broadcast RFID response (or that are positioned in an areawhere a broadcast RFID response has been received) may be selected tomake the signal strength determination. In either case, as described inrelation to steps 416 and 418 of FIG. 4, camera assemblies 600 that arebeing subjected to a signal strength that exceeds a preset thresholdlimit may then proceed to scan (i.e., pan and tilt) through their fullrange of motion. As depicted and described in relation to FIG. 7B, thesummed signal strength of the delayed and non-delayed antenna outputs ofa given vertical or horizontal antenna pair 622 will vary as a functionof respective vertical or horizontal angular position of the antennapair in relation to RFID tag 110. In a non-cluttered environment (e.g.,a non-reflective environment where a relatively clear path existsbetween transmitting RFID tag 110 and differential antenna array 621)this would result in the existence of only one absolute null LOSposition (e.g., where both horizontal and vertical null points coincide)which would correspond to alignment of the camera LOS with the RFID tag110, for example, to within about +/−5 degrees.

In one exemplary embodiment, once the selected PTZ camera assemblies 600of a visual locating system 300 have completed their scans, each cameraassembly 600 may return its scan results (e.g., visual image taken froma null LOS position at which both horizontal and vertical null pointsexist) to computer processor 310 of a visual locating system 300. In theevent only one null LOS position exists for each camera assembly 600,the computer processor 310 may display the visual images from eachcamera assembly 600 that is associated with the null LOS position to asystem operator, who may view and select the appropriate or desiredimage (e.g., as described in relation to steps 424 through 430 of FIG.4). In this regard, FIG. 9 illustrates one exemplary embodiment in whichtwo visual image windows 902 and 904 (e.g., taken at two null LOSpositions by the same camera) are simultaneously displayed via GUI oncomputer monitor 900. An operator may select the desired image (e.g.,step 430 of FIG. 4) by clicking with a mouse pointer on the appropriate“Select” button icon 906 or 908. Alternatively, the operator may requesta re-scan by the visual locating system 300 by clicking a mouse pointeron the “Rescan” button icon. It will be understood that FIG. 9illustrates just one simple exemplary embodiment of GUI that may beemployed in the practice of the disclosed systems and methods, and thatadditional selection features and/or different selection methods (e.g.,other than GUI display) may be alternatively or additionally employedthat are suitable for implementing one or more of the features describedherein.

Cluttered environments and obstructed RF paths may result in multiplenull LOS positions for a given camera assembly. As shown in FIG. 8, anobstructed RF path 818 may exist, for example, if a screen 810 or otherRF obstruction lies in-between the emitting RFID tag 110 and thereceiving differential antenna array 621 of a camera assembly 600, whilea clear RF path 820 is available to the differential antenna array 621from a highly RF reflective surface 812, e.g., such as a reflectivesurface of a flat metal panel on the side of a forklift. In the eventmultiple null LOS positions exist, the computer processor 310 maydisplay visual images associated with each respective multiple null LOSposition of a given camera assembly 600 to the system operator, who mayview and select the appropriate or desired image. For example, returningto the exemplary embodiment of FIG. 9, in the event of multiple nullpoints that result in two null LOS camera positions, both camera viewsmay be presented to the operator in the manner of visual image windows902 and 904 so that a final selection may be made in the manner asdescribed above. Once the selection has been made, the full view andzoomed view of the tagged object may be provided, for example, asdescribed earlier in relation to step 432 of FIG. 4 and as shown in FIG.5.

In one exemplary embodiment, a visual locating system may be configuredto gradually provide improved performance (i.e., more relevantselections) over time by automatically discarding null points and/ornull LOS positions based on selection/s made by an operator, e.g., thosenull LOS positions rejected by an operator that correspond to highlyreflective fixed location objects such as metal walls, soft drinkmachines, etc. For example, a computer processor 310 of a visuallocating system 300 may store in memory or otherwise record or rememberLOS positions for individual camera assemblies 600 corresponding torejected visual images or visual images specifically identified by anoperator for discarding from future scanning operations. In anotherexemplary embodiment, if an image/angular location is routinelydiscarded by the operator, a message may be displayed that asks if theoperator would like to place this solution at the bottom of the list interms of display priority. In yet another exemplary embodiment, it ispossible to categorize and/or store for future reference LOS positionsfor particular camera/s corresponding to particular identified objects,types of identified objects, etc. Using such stored LOS information, thehistory of movement (or non-movement) of an object throughout an areamay be stored and retrieved when desired, e.g., in graphical or textualform.

Alignment or re-alignment of a visual tracking differential antennaarray 621 with the LOS of an associated camera assembly optical block602 may be performed in any suitable manner and/or at any suitable timeor place (e.g., at the factory prior to system installation, in thefield after installation, etc.) In this regard, initial alignment of thedifferential antenna array may be performed, for example, at the factoryusing a known RFID tag source (i.e., having a fully characterized andunderstood signal strength/pattern under the alignment procedureconditions) and using automated correlation of the tag/target to thecenter of the LOS. This alignment may involve auto-correlation of theimage based on known visible characteristics of the tag/target. Tosupport this auto-correlation the tag may be embedded in a well definedoptical target.

Such an alignment procedure may be performed, for example, by mechanicalalignment of the LOS of a camera assembly optical block with anassociated differential antenna array in a shielded room or anechoicchamber. For example, during assembly a camera assembly optical blockmay be pre-aligned in a test jig so that the LOS of the optical block isdirectly pointed at and aligned with a known RFID target source. TheRFID source may be activated and RFID signals received by thedifferential antenna array. Based on the received RFID signals, aposition of the RFID target source may be calculated based on thedirectional line of reception of the differential antenna array. Usingthis calculated position of the RFID target source, the directional lineof reception of the differential antenna array may be compared to theLOS of the camera optical block (which is known to be aligned with theRFID target source). Based on this comparison, offset coefficients orother correction factors may be derived to correct for any differencebetween the directional line of reception of the differential antennaarray and the LOS of the camera optical block. Such correction factorsmay be, for example, stored in Flash or EEPROM memory (or any othersuitable data storage device of the camera assembly circuitry) and usedduring future camera assembly operation to adjust the directional lineof reception of the differential antenna array to match the opticalblock LOS.

Alternately, alignment of the LOS of a camera assembly optical blockwith an associated differential antenna array may be performed at ahigher level of assembly by visually aligning a LOS of a camera assemblyoptical block with a known RFID target source, e.g., by visuallyaligning a cross hair or other visual characteristic of the RFID targetsource with an optical block tick mark or electronically-generatedreticule that coincides with the LOS of the optical block. The RFIDsource may then be activated and RFID signals received by thedifferential antenna array used to compare the directional line ofreception of the differential antenna array with the LOS of thevisually-aligned camera optical block. Based on this comparison, offsetcoefficients or other correction factors may be derived and stored inthe camera assembly circuitry for future use in a manner as previouslydescribed. It will be understood the previously described alignmentprocedures are exemplary only, and that any other method suitable foraligning the LOS of a camera assembly optical block with an associateddifferential antenna array may be employed.

While the invention may be adaptable to various modifications andalternative forms, specific embodiments have been shown by way ofexample and described herein. However, it should be understood that theinvention is not intended to be limited to the particular formsdisclosed. Rather, the invention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theinvention as defined by the appended claims. Moreover, the differentaspects of the disclosed systems and methods may be utilized in variouscombinations and/or independently. Thus the invention is not limited toonly those combinations shown herein, but rather may include othercombinations.

REFERENCES

The following references, to the extent that they provide exemplarysystem, apparatus, method, or other details supplementary to those setforth herein, are specifically incorporated herein by reference.

U.S. Provisional patent application Ser. No. 60/437,711 entitled“Electromagnetic Circuit And Servo Mechanism For Articulated Cameras”,by Thao D. Hovanky.

Concurrently filed U.S. patent application Ser. No. 10/732,195 entitled“Electromagnetic Circuit And Servo Mechanism For Articulated Cameras”,by Thao D. Hovanky et al..

U.S. Provisional patent application Ser. No. 60/437,710 entitled“Systems And Methods For Actuating Lens Assemblies”, by Thao D. Hovanky.

Concurrently filed U.S. patent application Ser. No. 10/732,740 entitled“Systems And Methods For Actuating Lens Assemblies”, by Thao D. Hovanky.

U.S. Provisional patent application Ser. No. 60/437,712 entitled “SlipRing Apparatus”, by Richard G. Washington and Thao D. Hovanky.

U.S. Provisional patent application Ser. No. 60/437,690 entitled“Optical Block Assembly”, by Thao D. Hovanky and Richard G. Washington.

Concurrently filed U.S. patent application Ser. No. 10/732,924 entitled“Optical Block Assembly”, by Thao D. Hovanky and Richard G. Washington.

U.S. Provisional patent application Ser. No. 60/437,709 entitled“Thermoelectric Cooled Imaging Apparatus”, by Richard G. Washington andThao D. Hovanky.

Concurrently filed U.S. patent application Ser. No. 10/732,192 entitled“Thermally Cooled Imaging Apparatus”, by Richard G. Washington and ThaoD. Hovanky.

U.S. Provisional patent application Ser. No. 60/456,294 entitled“Systems And Methods For Creation, Transmission, And Viewing OfMulti-Resolution Video”, by Richard G. Washington.

1. A visual locating system, comprising: a plurality of cameraassemblies, each of said camera assemblies comprising an optical blockand a RF receiver, said RF receiver being configured to receive from aRF antenna one or more RF signals comprising a RFID broadcasttransmitted by a RFID device; and a computer processor in communicationwith each of said plurality of camera assemblies.
 2. The visual locatingsystem of claim 1, wherein said optical block of each of said cameraassemblies has a line of sight; and wherein the line of sight of saidoptical block of each of said plurality of camera assemblies isconfigured to move cooperatively with a directional line of reception ofa RF antenna.
 3. The visual locating system of claim 1, furthercomprising a plurality of differential antenna apparatus, each of saidplurality of differential antenna apparatus being associated with arespective one of said plurality of camera assemblies and beingconfigured to provide one or more RF signals comprising a RFID broadcasttransmitted by a RFID device to a RF receiver of said respective one ofsaid plurality of camera assemblies; and wherein said differentialantenna apparatus is configured so that a directional line of receptionof said differential antenna apparatus moves cooperatively with movementof the line of sight of said optical block of said respective one ofsaid plurality of camera assemblies.
 4. The visual locating system ofclaim 1, wherein each of said plurality of camera assemblies comprises adifferential antenna apparatus, said differential antenna apparatusbeing configured to receive and provide one or more RF signalscomprising a RFID broadcast transmitted by a RFID device to said RFreceiver of said respective camera assembly.
 5. The visual locatingsystem of claim 4, wherein each of said plurality of camera assembliescomprises a PTZ camera assembly.
 6. The visual locating system of claim5, wherein each of said plurality of camera assemblies comprises adifferential antenna array.
 7. The visual locating system of claim 4,wherein said differential antenna apparatus of each of said plurality ofcamera assemblies is directionally aligned with an optical block of saidrespective camera assembly.
 8. The visual locating system of claim 7,further comprising signal processing circuitry configured to receivesaid one or more RF signals from said differential antenna apparatus,and to provide a differential output signal based upon said one or moreRF signals.
 9. The visual locating system of claim 7, further comprisingsignal processing circuitry conflaured to receive said one or more RFsignals from said differential antenna apparatus, and to provide one ormore signal strength signals based upon said one or more RF signals; andwherein said signal processing circuitry is configured to identify andselect one or more of said signal strength signals that are indicativeof a RF signal strength value that exceeds a minimum RF signal strengthvalue.
 10. The visual locating system of claim 1, wherein each of saidplurality of camera assemblies further comprises a RF transceiver andsaid RF antenna; and wherein said RF transceiver is configured toprovide a RF signal comprising RFID device activation data to said RFantenna of said respective camera assembly.
 11. The visual locatingsystem of claim 10, wherein said RF antenna of each of said plurality ofcamera assemblies comprises a differential antenna apparatus.
 12. Thevisual locating system of claim 1, wherein said plurality of cameraassemblies of said visual locating system are installed in a passengerterminal.
 13. The visual locating system of claim 12, wherein saidpassenger terminal comprises an airport.
 14. The visual locating systemof claim 1, wherein each of said camera assemblies comprises an RFreceiver embedded in said camera assembly and configured to receive froma RF antenna one or more RF signals comprising a RFID broadcasttransmitted by a RFID device.
 15. A method of locating objects in apassenger terminal, comprising: associating a first RFID device with apassenger; and locating said passenger within said passenger terminalusing a RF transmission broadcast by said first RFID device; whereinsaid method comprises visually locating said passenger within saidpassenger terminal using at least one camera assembly; and wherein saidcamera assembly comprises an optical block and an RF receiver configuredto receive from a RF antenna one or more RF signals comprising said RFtransmission broadcast by said first RFID device.
 16. The method ofclaim 15, wherein said RF antenna comprises a differential antennaapparatus; and wherein said method further comprises: receiving said oneor more RF signals in said RF receiver from said differential antennaapparatus; and wherein the line of sight of said optical block of saidat least one camera assembly is configured to move cooperatively with adirectional line of reception of said differential antenna.
 17. Themethod of claim 15, wherein said first RFID device is attached to orcontained within a RFID carrier assigned to said passenger.
 18. Themethod of claim 17, wherein said RFID carrier comprises a ticket holderor a ticket assigned to said passenger.
 19. The method of claim 15,wherein said method comprises visually locating said passenger withinsaid passenger terminal using at least one camera assembly having afield of view corresponding to a location of said RF transmissionbroadcast by said first RFID device.
 20. The method of claim 19, whereinsaid method comprises visually locating said passenger within saidpassenger terminal using a plurality of camera assemblies, wherein saidpassenger is visually located by selecting one or more of said cameraassemblies having a field of view corresponding to a location of said RFtransmission broadcast by said first RFID device.
 21. The method ofclaim 20, wherein each of said plurality of camera assemblies comprisesan optical block and a RF receiver, said RF receiver being configured toreceive from an antenna an RF signal comprising said RF transmissionbroadcast by said first RFID device.
 22. The method of claim 20, whereinsaid method further comprises tracking said passenger within saidpassenger terminal using a visual locating system, said visual locatingsystem comprising: said plurality of camera assemblies, each of saidcamera assemblies comprising an optical block and a RF receiver, said RFreceiver being configured to receive from a RF antenna one or more RFsignals comprising a RFID broadcast transmitted by said first RFIDdevice; and a computer processor in communication with each of saidplurality of camera assemblies.
 23. The method of claim 22, wherein eachof said plurality of camera assemblies further comprises a differentialantenna apparatus, said differential antenna apparatus being configuredto receive and provide one or more RF signals comprising a RFIDbroadcast transmitted by said first RFID device to said RF receiver ofsaid respective camera assembly.
 24. The method of claim 23, whereineach of said plurality of camera assemblies comprises a PTZ cameraassembly.
 25. The method of claim 24, wherein each of said plurality ofcamera assemblies comprises a differential antenna array.
 26. The methodof claim 23, wherein said differential antenna apparatus of each of saidplurality of camera assemblies is directionally aligned with an opticalblock of said respective camera assembly.
 27. The method of claim 23,wherein said differential antenna apparatus is directionally alignedwith a line of sight (LOS) of said optical block of said camera assemblyunit; and wherein said visual locating system is configured to alignsaid LOS of said optical block with a position of said passenger withthe location of the source of said RFID broadcast transmitted by saidfirst RFID device by determining the relationship between said LOS andsaid source location by analyzing the emitted signals from said firstRFID device.
 28. The method of claim 22, wherein each of said pluralityof camera assemblies further comprises a RF transceiver and said RFantenna, said RF transceiver comprising said RF receiver or saidrespective camera assembly; and wherein said RF transceiver isconfigured to provide a RF signal comprising RFID device activation datafor said first RFID device to said RF antenna of said respective cameraassembly.
 29. The method of claim 28, wherein said RF antenna of each ofsaid plurality of camera assemblies comprises a differential antennaapparatus.
 30. The method of claim 15, further comprising: associating asecond RFID device with a luggage item or carry on item of saidpassenger; and at least one of: locating said luggage item within theluggage handling areas of said passenger terminal or on a passengervehicle using a RF transmission broadcast by said first RFID device; orlocating said carry on item within said passenger terminal using a RFtransmission broadcast by said second RFID device; or a combinationthereof.
 31. The method of claim 30, wherein said method compriseslocating said carry on item within said passenger terminal using a RFtransmission broadcast by said second RFID device, and detecting whensaid location of said passenger differs from said location of said carryon luggage by a predetermined distance.
 32. The method of claim 30,wherein said method comprises locating said luggage item within theluggage handling areas of said passenger terminal or on a passengervehicle using a RF transmission broadcast by said first RFID device, anddetecting when said passenger has not boarded the same passenger vehicleinto which said luggage item has been loaded.
 33. The method of claim30, wherein said method comprises visually locating said luggage itemwithin said luggage handling areas using a plurality of cameraassemblies, wherein said luggage item is visually located by selectingone or more of said camera assemblies having a field of viewcorresponding to a location of said RF transmission broadcast by saidsecond RFID device.
 34. The method of claim 33, wherein said methodfurther comprises tracking said luggage within said luggage handlingareas using a visual locating system, said visual locating systemcomprising: a plurality of camera assemblies, each of said cameraassemblies comprising an optical block and a RF receiver, said RFreceiver being configured to receive from a RF antenna one or more RFsignals comprising a RFID broadcast transmitted by said second RFIDdevice; and a computer processor in communication with each of saidplurality of camera assemblies; wherein each of said plurality of cameraassemblies further comprises a differential antenna apparatus, saiddifferential antenna apparatus being configured to receive and provideone or more RF signals comprising a RFID broadcast transmitted by saidsecond RFID device to said RF receiver of said respective cameraassembly; and wherein said differential antenna apparatus isdirectionally aligned with a line of sight (LOS) of said optical blockof said camera assembly unit; and wherein said visual locating system isconfigured to align said LOS of said optical block with a position ofsaid luggage item with the source location of said RFID broadcasttransmitted by said second RFID device by determining the relationshipbetween said LOS and said source location by analyzing the emittedsignals from said second RFID device.
 35. The method of claim 15,wherein said passenger terminal comprises an airport.
 36. The method ofclaim 15, further comprising associating a photograph of said passengerwith an identity of said first RFID device; receiving said RFtransmission broadcast by said first RFID device at a station in saidpassenger terminal; and displaying said photograph for identityverification purposes at said station based upon receipt of said RFtransmission broadcast at said station by said first RFID device. 37.The method of claim 15, wherein said RF receiver is embedded in saidcamera assembly.
 38. A method of visually locating objects, comprising:associating a RFID device with an object; providing a camera assemblyunit comprising an optical block and a RF receiver, said RF receiverbeing configured to receive from an antenna an RF signal comprising aRFID broadcast transmitted by said RFID device; receiving a RFIDbroadcast transmitted by said RFID device, said RFID broadcast beingreceived by said RF receiver from said antenna; and visually locatingsaid object usingsaid optical block of said camera assembly based onsaid RFID broadcast received by said RF receiver from said antenna. 39.The method of claim 38, wherein said antenna comprises a differentialantenna apparatus; and wherein said method further comprises: receivingsaid RF broadcast in said RF receiver from said differential antennaapparatus; and moving a directional line of reception of saiddifferential antenna apparatus cooperatively with movement of the lineof sight of said optical block to visually locate said object using saidoptical block.
 40. The method of claim 38, wherein said camera assemblyunit further comprises an RF transceiver, and wherein said methodfurther comprises transmitting a RF signal comprising RFID deviceactivation data to cause said RFID device to transmit said RFIDbroadcast.
 41. The method of claim 38, wherein said camera assembly unitfurther comprises a differential antenna apparatus, and wherein saidmethod further comprises using said differential antenna apparatus toreceive and provide said RF signal comprising a RFID broadcasttransmitted by a RFID device to said RF receiver.
 42. The method ofclaim 41, wherein said camera assembly unit comprises a PTZ cameraassembly unit.
 43. The method of claim 38, wherein said RF receiver isembedded in said camera assembly unit.
 44. A method of visually locatingobjects, comprising: associating a RFID device with an object; providinga camera assembly unit comprising an optical block and a RF receiver,said RF receiver being configured to receive from an antenna an RFsignal comprising a RFID broadcast transmitted by said RFID device;receiving a RFID broadcast transmitted by said RFID device, said RFIDbroadcast being received by said RF receiver from said antenna; andautomatically visually locating said object using said optical block ofsaid camera assembly based on said RFID broadcast received by said RFreceiver from said antenna.
 45. A visual location system, comprising: aplurality of camera assemblies, each of said camera assembliescomprising an optical block and a RF receiver; wherein said RF receiveris configured to receive from a RF antenna one or more RF signalscomprising a RFID broadcast transmitted by a RFID device; and whereinsaid visual location system is configured to automatically visuallylocate said object using said optical block of said camera assemblybased on said RFID broadcast received by said RF receiver from saidantenna.